Recessed lighting fixture



Septo 24, 1963 c. J. STUART ET AL RECESSED LIGHTING FIXTURE 2Sheets-Shec-ztl l Filed Deo. 14, 1959 Sept. 24, 1963 c. J. STUART ETALRECESSED LIGHTING FIXTURE 2 Sheets-Sheet 2 Filed Dec. 14, 1959 o ww .Nw\N um |Lp a United States Patent() The present invention relates torecessed lighting fixtures.

. 'Lighting fixtures of the type which in use are mounted in recessedrelation inwalls, ceilings, or the like, encounter the problems ofsubjection of the wiring to possibly excessive heat developed by thelamp or light bulb employed in the fixture, and of the need foraccessibility of the wiring from the interior of the fixture. Thefixture construction of the present invention provides solutions tothese problems representing improvements over previous structures ofthis type.

It is an important object of the invention to provide a recessedlighting fixture construction which greatly minimizes both the radiationand conduction of heat so as :to protect the wiring against thedeleterious effects thereof, and at the same time provides for easyaccess to the wiring when desired.

Another object is the provision of a recessed lighting fixture in whichsubstantially the entire interior of the fixture housing 4is shieldedAfrom the radiant heat of the lighting means.

Another object is the provision of a recessed lighting fixture employinga heat-dissipating mount `for the lighting means provi-ding `a limitedcircuitous heat-conducting path between the lighting means and thehousing to minimize transmission of heat to lthe housing.

A further object is the provision of a recessed lighting fixture inwhich a reflector is mounted in completely heat-insulated relation tothe housing.

Another object of the invention is the provision of a recessed lightingfixture employing unitary means for both closing the wiring-accessaperture and mounting the lighting means which also provides a heatinsulating space and a heat baffle plate within the housing to minimizeheat transfer to the wiring.

A further object is the provision of a recessed lighting fixtureincluding a junction box mounted on and accessible from the fixturehousing in which the junction box is spaced from the housing and an airpassage or open ended chamber is defined between the box and housing tominimize heating of the `junction box.

Another object is the provision of a recessed lighting fixture Ihaving ajunction box mounted thereon in spaced relation, inwhich a plurality ofcooling air spaces or passages 'are provided to minimize transmission ofheat to the box.

A rfurther object is the provision of ia recessed lighting fixture whichincludes a junction box mounted on the fixture housing in spacedrelation thereto and with a cooling air passage defined therebetween, inwhich protective shielding means is provided for wiring extendingthrough sai-d space -from the housing to the box.

lIt is also an object of the invention to provide a recessed lightingfixture in which a reflector is mounted on the top wall of the fix-turehousing in spaced relation thereto by a tubular heat-insulating spacerand a single fastening element itself' also insulated from thereflector.

Other and further objects, advantages, and features of the inventionwill be apparent to those skilled in the art from the following.detailed description, taken in conjunction with the accompany-ingdrawings, in which:

FIG. 1 is a side elevational view of a lighting fixture according to thepresent invent-ion, with portions broken away and portions shown insection for greater clarity of disclosure;

FIG. 2 is a cross-sectional view taken substanually as indicated by theline 2-2 of FIG. l; and

FIG. 3 is a bottom plan view of the fixture with the closure removed.

Referring to the drawings, there is shown a fixture embodying thepresent invention, in which a housing generally indicated as 10 isdefined by a rectangular top wall 11 and four side walls l12 extendingfrom the edges of the top wall, with the side wall edges remote from thetop wall defining an open bottom 13 of the housing. The fixture isillustrated as mounted within a ceiling C indicated in dotted lines, inwhich ian opening is formed of sufficient size to allow the insertion ofthe housing from below. A closure generally designated 14 is providedfor the open housing bottom, comprising a rectangular bezel or trimmember 15 in which i-s mounted a lens or plate of glass 16 or othersuitable light-transmitting material. The trim member has across-sectional width sufficient to conceal lthe edges of the housingside walls 12 and of the opening in the ceiling C. About theglass-receiving opening of the trim member I15 extends a flange 17 whichholds the glass 16 against lateral movement, and projects within theopen bottom of the housing when the closure 14 is in its closingposition, the flange 17 paralleling'lthe respective side walls 12 andbeing spaced inwardly therefrom throughout its extent. The closure isremovably secured to the housin and held in closed position relativethereto, by a pair of spring members 18 pivoted on the flange 17 as byrivets 19 to extend yalong opposite side walls 12 of the housing 10, thespring members 18 engaging in slotted spring brackets 20 secured tosuc-h opposite housing side walls as by screws 21. The spring membersprovide for a resilient connection yieldably holding the closure on thehousing. Since the spring members 1S and brackets 20 form no part of thepresent invention, and may be replaced with other suitable means foraccomplishing the same purpose, the details of construction andoperation thereof are omitted. Any suitable means may be employed formounting the fixture, but in the present instance there is illustrated apair of mounting brackets 22 each having a plate portion 2.3` ldisposedagainst the interior of one of the walls 12 on which the brackets 20 aresecured. Outwardly offset leg portions 24 extend yfrom the plate portion23 of each bracket 22 and project through suitable apertures 25 formedin the ladjacent side walls 12, land extend parallel to the outer facesof the walls. Outwardly extending foot portions 26 on the Ileg portionsare adapted to engage on the upper surface of the ceiling C, as bestshown in FIG. 2, and to be secured thereto if desired. Slots 27 in theplate portions 23 receive therethrough screws 28 threaded through theside walls, to provide for vertical adjustment of the brackets 22relative to the housing 10 so as to Idetermine the vertical position ofthe housing relative to the ceiling, as will be understood. In thepresent instance, the `foot portions 26 are not shown as secured to theceiling C, the housing being secured by a clamping arrangement. Theclamping action is provided fby a pair of mounting angle members 3G eachof which has one leg 31 thereof extending into the interior of thehousing along the adjacent Iside wall and secured by the screw 21 whichsecures the spring bracket 20. The other leg 32 of the ang-le memberextends outwardly below the edge of the side wal-l to engage the lowersurface of the ceiling C, so that the ceiling is in effect clampedbetween the foot portions,

extending legs 32 are concealed by the trim member 15.

connected at one endiby. a preferablyy integral wall,

35', and each having at the opposite end thereof an outturned ilange37". .The box is completed by a bottom plate 38 and a cover plate 39,the plate 38 being secured in place by spot wel-ding to suitable flangesof the walls 35, and the plate 39 being removably secured in any wellknown manner. The side or end of the box 34 opposite that at which thewall 36 extends vis open so as to allow access into the box through theYaperture 33, the box being mounted on the apertured side wall 12pt thehousing by means of the flanges 37. These ilanges engage the innersurface `of the wall adjacent the oppositeY ends of the aperture y33 andare secured to the wall by means of screws 40. The plates 33 and'39extend from the Wall 36 only a portion. of the distance between that endwall and the housing wall l2, the width of the plates 38 and 39 beingshown in FIGS. l and 3 as substantially half the -distance between thewall 36 and the llanges member or support member 4l ofgeneral U-shapeinV cross section, comprising a closure plate 42 and a mounting plate 43connected to the closure plate along one edge by'a preferably integralportion 44 which holds the plates 42 and 43 in suitably spaced andsubstantially parallel relation. The 'member4l is secured on theinterior of the side wall l2, extending over the aperture 33, by meansofscrews 45 extending through the closure plate 42 and the housing wall.Suitable apertures 46 are formed in the moun-t-ing plate 43 to per-mi-tapplication and removal of the'screws `45, as Will be clear from FIG. 2.As best evident trom FIGS. 2 and 3, the cover plate 42 overlies thellanges`37 of the junctionbox 34 and the securing screws 4d thereof. Toaccommodate the heads of these screws, the `cover plate is provided withappropriately located `apertures 47 (FIG. 2).

Secured to the U-shapedV support rnember4l is a U- shaped heat'ballemeans'extending between the walls 35. The baille means :comprise a pairof substantially parallel vertically arranged spacing plates 48 eachhaving an inturned flange 49 secured to the closureV plate 42 as by spot-weldingand extending outwardly from the plate 42y to an integraltransversely extending baille plate 50. The plate t) is disposed justwithin the adjacent edge portions of the plates 38 and 39 of thejunction box 34 and extends therebetween, as best shown in FIGS. l `and3, to kdefine with'the wal-ls 35 and 36 and the plates 3S and 39 ajunction compartment 5l within which the wiring Econnections `for thexture are enclosed. The baille plate, as shown, is preferably slightly`smaller than the wall 36 to which it` lies parallel, but is of suchdimensions as to substantially close the compartment, as is evident fromthe drawing. lt will be apparent that the compartment 5l may beconsidered as a junction box of smaller size than the junctionbox 34,held in spaced relation to the housing side wall by the porti-ons of thewalls 35 extending between the'housing and the com' partment and ineffect forming spacing extensions of .a pair of opposed walls of the boxor compartment'Sl.'

chamber 52 defined between the walls 35 by the closure plate 42,.spacing plates 48, and baffle plate 50. This passage or vair chamber 52permits free circulation of air between the housing and the'junctionIbox or compartment 5l Vto assist in maintaining the latter in areasonably cool condition. Auxiliary air passages or spaces 53 (FIG. 3)are defined between the baille spacing plates 43 and the adjacentportions or extensions of the walls 35, and serve to cool the walls soas to reduce the possible conduction of heat through thewalls 35 to thejunction compartment.

An electrical socket 55 for the light bulb (not shown) employed in thelixture is mounted on the mounting plate 43 by means of a screwA 56 orthe like, an embossment 57 of the plate 43 engaging in a correspondingrecess in the base of the socket to hold the socket against rotationwithout requiring more than one securing screw 56. A

disc 53 of heat-insulating material, which may also be electricallyinsulating, is disposed between the socket 55 I-t may l land themounting plate 43 therefor to minimize conduction of heat therebetween.Wires 59 lead from the socket tothe junction box, passing through thechamber 52. Extending across the chamber 52, with itsY ends suitablyreceived in apertures formed in the plate 42 `and lthe baille plate 50,is a tube 6l) of suitable heat insulating material which may also haveelectrical inusllatirrg properties,V

which encloses the portion of the wires 59 within the air chamber toprotect the same from the effect of heat transmitted from the lightbulb. The tube 4oil may be suitably held in place by being resilientlypressed between the closing plate 42 and baille plate 5u, which may beslightly distorted by the tube.

The junction box may be mounted on the housing 10 in initial assembly ofthe xture, and upon installation of the fixture, with the closure 14 andthe rellector 6.1 removed, the wires 59 may be connected to theelectrical conductors (not shown) leading from the mains to the junctionbox or compartment. `Such conductors ordinarily are protected bysuitable rigid or flexible conduit an end of which may be lconnected tothe' junction box. In making the wiring connections, several inches ofexcess or slack of the conductors is provided for, either by providingsuch a length of the conductors beyond the end ot the conduit, or inthecase of flexible conduit allowing such an ,excess of the conduitoutsideof the junction box itself.- To make the connections, the U-shapedsupport member 41 with the socket 55 and the baille plate 50 carriedthereby is disengaged from the housing by removal of `screws 45, and theconductors are drawn out to a point where their ends may be engaged withthe socket lead wires 59. This may be done either by using the slack inthe conductors or by moving the junction box inwardly upon removal `ofscrews 4t), as most convenient. The connections may thus be made eitherwithin the area bounded by the walls 35 or at a point inwardly of theplane of the sidewall. With the junctionbox supported by means of thellanges 37 secured to the housing Vby the screws 40, and with theconnections completed,

Y ber 4l with the parts secured thereon may be removed .explained andythe' wires 59 drawn inwardly of thehousing,` with or,

without the junction box being similarly moved inwardly orf the housingas already explained, to bring the connections within reach,either-through the laperture 33 or within the outline of the housing.Replacement of the parts may thereafter be made in the manner alreadyThe U-shaped support member 41 provides not only a closure for theaperture 33 affording access to the junction box, but also carries thebaffle means and therewith defines the air passage or open ended chamber52 and the auxiliary air spaces 53, as already explained. The memberalso serves as a mounting bracket for the socket 55. The member 41preferably is secured in the housing in such fashion that the free edgeof the mount-ing plate 43 is spaced from the housing so as not tocontact .therewith and thus avoid providing a heat-conductive paththereto. Instead, the member 41 provides a restricted circuitousheat-conducting path Afrom the connecting portion 44 to the plate 42 andadjacent side wall, the connection ofthe plates 42 and 43 along only oneedge thereof Iand the spaced relation of the plate 43 assuring suchlimited conductive path. The plate 4S is made substantially as shown,that is, of substantially the saine size las the plate 4Z, so that itmay aid inthe dissipation of heat which may be transmitted thereto.Instead of spacing Athe plate 43 from the housing, it may, it desired,beV arranged to engage against any appropriate portion of the housing,such -as the top wall 11, to -rigidify the mounting of the socket 55andalso to provide Ia second path for the conduction of heat to the xturehousing for dissipation thereby, when the circumstances are such thatsuch a second path is advantageous. The member 41 provides an insulatingspace between the plates 42. 'and 43 by reason of the spaced relationthereof, and also provides a heat baffle in addition to the baffle plateSil which acts to minimize radiation of heat to the junction box.

In the housing there is provided the reflector 61, of suitably concaveform, which is directed toward or farces the open bottom 1-3 of thehousing. The reector is illustrated as `o rf frusto-pyramidal form, witha rectangular fiat top portion 62 from which ffour side walls 63 inclineoutwardly and downwardly to define the open lower edge 64 of thereflector. An aperture 65 is formed in one of the reflector side walls63 to allow the socket 55 to project Within the reflector and hold thelight bulb in proper position. As most clearly shown in FIG. 3, thereflector 6l at its edge 64 has a perimeter generally corresponding tothe interior of the housing, but orf slightly Smaller dmensions, so thatit is spaced from the housing and from the trim flange 117 at allpoints, and furthermore is spaced from all parts of the structure whichcontact the housing. By reason of such spacing, there is no conductionof heart from the lighting fixture bulb to the housing or other parts bythe reflector 61. The top portion of the reflector is formed with lacentral aperture providing an edge portion which engages in lacircumferential groove adjacent one end of a tubular spacer 66 formed ofheat-insulating material. The spacerextends between the reflector andthe top Wall 11 of the housing to receive therethrough a screw 67 thehead of which is insulatingly spaced from the reflector by the end ofthe spacer lying within the reflector, and the threaded shank of whichextends through a suitable aperture in tne top wall to hold the spacer66 against the wall and thereby clamp the reflector securely in the`desired position. The reflector may be torrned of suitable sheet metaland may of course have a configuration other than that specificallydisclosed. The relatively short length ot the tubular spacer 66 assuresthe necessary degree of stability of the reflector which could not beprovided by a long spacing member.

j As shown in FIGS. l and 2, the Ireflector 61 extends within the flange17 of the trim 1S, the edge or the reflector lying in a plane below theplane orf the edge of flange 17, so that the Harige Iand refiectorextend in overlapping relation. The margin of the reflector, as alreadymentioned, is spaced from and surrounded by flange 1'7. Completeshielding of the Ihousing from heat radiated by the light bulb is thusachieved, since the flange 17 serves asa .deflector for rays from thelight bulb, and by reason of its overlapping relation to .the reflectorcooperates therewith to prevent heat rays impinging on the housing.

It will be evident that the provision of the socket-receiving aperturein the reflector instead of the usual edge slot contributes to thesubstantially complete shielding of the housing inte-rior. Except forheat absorbed by the reflector 61 and flange 17, all of the heatradiated by the light bulb either passes directly through the glass 16of the housing closure 14, or is refiected therethrough. Since both thereflector 61 and the flange 1'7 are spaced from the housing and fromeach other, there is no conduction of heat therefrom to the housing andonly such heat as is transmitted by convection or by re-radiation fromthe refiector or flange can reach the housing, together with such minorproportion as rnay be conducted through the insulating spacer 66 andscrew 67 or pass about the socket 55 through the aperture 65'. Becauseof the confined locations in which lighting fixtures of the type hereindisclosed are normally installed, the insulation of associatedelectrical conductors would be subjected to such a great concentrationof heat as to deteriorate very quickly to the danger point, if specialprovision were not made to maintain the 'conductors at a reasonably low,safe temperature. The present construction accomplishes this in a mostthorough and effective rnanner.

As .already pointed out, the U-shaped supporting member 4l provides botha baille and an insulating air space interposed directly between thesource of heat and the junction box mounted on Ithe housing, and thus inlarge degree prevents radiation of heat to the wiring in the junctionbox. The conduction of heat through the socket 55, normally the coolestportion of the lighting means and as a practical matter heated only bythe light bulb, is largely minimized by the heat-insulating disc 58ldisposed between the socket and the member 4,1 and further by thelimitation of the heat conductive path provided by the U-shapedconstruction of the member 41, `as previously explained. Transmission oflieat to the junction box by conduction from the housing is minimized bythe fact that the only heat-conductive path to the junction box isthrough the walls 35. It is further reduced by the cooling effect of theopen-ended fair spaces 52 and `53 on the walls 35, so that much of theheat being conducted through fthe walls is dissipated. The provision ofthe tube 6i) lfurther lim-its conduction of heat to the compartment 51,since in addition to protecting the wires 59 against the effects ofradiated heat, it does not itself conduct any appreciable quantity ofheat to the compartment 51, and provides a heataradiating surface todissipate heat conducted through the wires 59 themselves.

We claim:

l. A recessed lighting fixture comprising a housing defined by side andtop walls and having an open bottom, a junction box mounted on a sidewall of said housing including a first pair of opposed walls secured tosaid side wall and a second pair of walls laterally termin-ating inspaced .relation to said housing side wall and connecting said firstwall pair, `an opening in the side wall affording access to the junctionbox, a closure for said opening, a heat bafile plate carried by saidclosure in such spaced relation as to extend between said second pairoef box walls at the edge portions thereof adjacent the housing andbetween said first pair of walls to define a substantially closedcompartment in said juncture box, means connecting said baffle plate .tothe closure including a pair of plates integral with the baffle plateextending parallel to the walls of said first pair to define a pair oflaterally outer open spaces therewith and to ldefine with said bailleplate an inner open space between said compartment and the housing,.said closure comprising a pair of parallel plate members connectedalong one parir of adjacent edges, one of said plate members beingsecured to said housing side wall and extending over said opening andthe other being spaced inwardly from the housing side wall and disposedout of contact with the housing, a heat-insulating tube extendingbetween `apertures in said one plate member and said baffle plate toenclose wiring extending between the housing land said compartment, anelectrical socket mounted on the other plate member, la heat insulatingmember disposed between said socket and other plate member, a concavereiiector in the housing having an aperture spaced from the edge`thereof receiving the socket therethrough, heat-insulating callyoverlapping laterally spaced relation to the reliectory and spaced :fromthe housing side walls.

2. A recessed lighting fixture comprising ar housing defined by side andtop walls and having an open bottom, a junction box mounted on a sideWall of said housing having a pair of opposed walls thereof terminatingin spaced relation to said housing sidewall, an opening in the side wallaffording access to the Vjunction box,'aV

closure for said opening, a heat baiiie plate carried by Y said closurein such spaced relation as to extend between said pair of box walls atthe edge portions thereof adjacent the housing to define a substantiallyclosed compartment in said junction box and an open space between saidcompartment and the housing, said closure comprising a pair of parallelplate members connected along one pair of adjacent edges, one of saidplate membersV being secured to said housing side wall and extendingover said opening and the other being spaced from the housing,

an insulating Vtube extending between apertures in said one plate memberand said baffle plate to enclose wiring extending between the housingand said junction box compartment, an electrical socket 4mounted on theothery plate member, a concave reiiector in the housing extending oversaid socket, heat-insulating spacing means extending between the centerof said reflector and the top wall of the housing and having a portionwithin the reflector, and fastening means securing the reflector inplace extending from the reiiector to said top wall through said spacingmeans and held out of contact with the reiiector Vby the spacing meansand holding the reflector out of contact with the housing.

3. A recessed lighting fixture comprising a housing defined by sidewallsand a top wall and having an open bottom, a junction box mounted on aside wall of said housing having a pair of opposed walls thereof saidhousing Vhaving a pair of opposed wallsV thereof terminating in spacedrelation to said housing side wall, an opening in the side wallaffording access to the junction Y box,ra closure for said opening, aheat bafiie plate carried Y terminating in spaced relation to said sidewall whereby v terminating in spaced relation to said housing side wall,

an opening in the side wall affording access to the'V junc-` tion box, aclosure for said opening', a heat baflic plate carried by said closurein such spaced relation as to extend between said pair of box walls atthe edge' portions thereof adjacent the housing to dene a substantiallyclosed compartment in said junction box and an open space between saidcompartment and the housing, said closure comprising a pair of parallelplate members connected along one pair of adjacent edges, one of saidplate members being securedV to said housing side wall yand Vextendingover said opening and the other being spaced from the housing, a heatand electrical insulating tube engaged in and extending betweenapertures in said one plate member and said baffle plate to enclosewiring extending between the housing and said junction box compartment,an electrical socket mounted on the Vother plate member, a concavereiiector in the housing for the aperture, lheat baffle by said closurein such spaced relation as to extend between said pair of box walls atthe edge portions there- Y of adjacent the housing to define asubstantially closed` compartment in said junction box and an open spacebetween said compartment and the housing, said closure other platemember, a concave reflector in the housingl extending over the socket,and heat-insulating means mounting the reflector Vin the housing out ofcontact therewith.

5. A recessed lighting Yfixture `comprising la Yhousing defined by sideand top walls and having an open bottom, an aperture in a side wall ofthe housing, a junction box mounted on said side wall accessible throughsaid aperture, a closure for the aperture including a rst plate membersecured to the side wall over the aperture and a second plate membersecured to said first plate member only along an edge thereof and spacedtherefrom, an electrical socket mounted on said second plate member, anda concave reiiector heat-insulatingly a iirst pair of opposed verticallydisposed wall ymembers of the box extending and 4secured to 'the housingside Wall at opposite ends of the aperture, closure means means mountedon said closure means including a vertical baffle plate spaced from theside wall `extending between said first wall member pair and with saidclosure means defining an Y open-ended air chamber, said baffle meansalso including plate members integral with the bathe plate andextending' defining with said first pair and said baiiie plate ajunction t compartment separated from said housing by said air chamber,said second pair of opposed wall members said opcn-ended air chamber andsaid open-ended air spaces communicate with the atmosphere surroundingthe junction box so as to permit a iiow of air therethrough.

i7. A recessed lighting fixture comprising a housing having an aperturedside Wall, a junction box having an open end, means mounting said box onsaid side wall in spaced relation thereto with said open end facing theside Wall, a first closure member for said aperture and a second closuremember for said open end, at least vone of said closure members beingresilient, and a tube of heat and electrical insulating materialextending between said closure members and removably held in position bybeing resiliently pressed therebetween for protectively enclosing Wiringextending between the housing and box.

8.-A recessed lighting fixture comprising a housing l defined by sideand top walls and having an open bottom,

a concave reflector in said housing directed toward said open bottom andhaving a central aperture, a tubular spacing member of heat-insulatingmaterial disposed betweenl said top wall and reflector and having aportion extending through said aperture, and a headed fastener extendingthrough the aperture and spacing member into retaining engagement withthe top wall and held out of contact withthe reflector by said vspacingmember portion.

9. A recessed lighting fixture of ,the type set forth in claim 7characterized by said closure members each having an aperture thereinand said tube of insulating material having reduced end portionsaccommodated Within said apertures respectively.

References Cited in the le of this patent UNITED STATES PATENTS1,418,671 Patterson June 6, 1922 1,580,090 Shoenberg Apr. 6, 19261,919,558 Johnson July 25, 1933 2,076,650 Kettron Apr. 13, 19372,233,947 Kantack Mar. 4, 1941 2,554,258 Lundquist May 22, 1951 10 Reseket al Dec. 4, 1951 Beber et al Dec. 27, 1955 McGinty et al Oct. 16, 1956Isler Aug. 6, 1957 Kingman Oct. 21, 1958 McGinty Aug. 4, 1959 De MauroAug. 11, 1959 Bodian Apr. 4, 1961 Schwartz Aug. 22, 1961 OTHERREFERENCES Inspiration-Lighting, page M43, catalogue published by MoeLight Division of Thomas Industries Inc., Fort Atkinson, Wisconsin, dateof publication, 1955.

4. A RECESSED LIGHTING FIXTURE COMPRISING A HOUSING DEFINED BY SIDE WALLS AND A TOP WALL AND HAVING AN OPEN BOTTOM, A JUNCTION BOX MOUNTED ON A SIDE WALL OF SAID HOUSING HAVING A PAIR OF OPPOSED WALLS THEREOF TERMINATING IN SPACED RELATION TO SAID HOUSING SIDE WALL, AN OPENING IN THE SIDE WALL AFFORDING ACCESS TO THE JUNCTION BOX, A CLOSURE FOR SAID OPENING, A HEAT BAFFLE PLATE CARRIED BY SAID CLOSURE IN SUCH SPACED RELATION AS TO EXTEND BETWEEN SAID PAIR OF BOX WALLS AT THE EDGE PORTIONS THEREOF ADJACENT THE HOUSING TO DEFINE A SUBSTANTIALLY CLOSED COMPARTMENT IN SAID JUNCTION BOX AND AN OPEN SPACE BETWEEN SAID COMPARTMENT AND THE HOUSING, SAID CLOSURE COMPRISING A PAIR OF PARALLEL PLATE MEMBERS CONNECTED ALONG ONE PAIR OF ADJACENT EDGES, ONE OF SAID PLATE MEMBERS BEING SECURED TO SAID HOUSING SIDE WALL AND EXTENDING OVER SAID OPENING AND THE OTHER BEING SPACED FROM THE HOUSING, AN ELECTRICAL SOCKET MOUNTED ON THE OTHER PLATE MEMBER, A CONCAVE REFLECTOR IN THE HOUSING EXTENDING OVER THE SOCKET, AND HEAT-INSULATING MEANS MOUNTING THE REFLECTOR IN THE HOUSING OUT OF CONTACT THEREWITH. 